Starch paste



the application of which will .be indicated in Does not flow. the claims; 33532 213:2 tit? Heretofore it has been impossible to obtain a 221-8 m4 .8 2 satisfactory state of dispersion in ordinary $1; $1: 80

cooked starch paste, andthe product has been i%- Patented Feb. 13, 1934 I v I UNITED STATES PATENT OFFICE s'rnncn ms'rn Stephen Jozsa, New York, and Herbert G. Gore, Scarsdale, N. Y., assignors to Standard Brands Incorporated, Dover, Del., a corporation of Delaware No Drawing. Application January 11, 1930 Serial No. 420,286

.9 Claims. (Cl. 127-32) This invention relates to methods of preparent invention may be carried out, the starch ,ing starch solutions of low viscosity, and has paste may be prepared by heating about 1900 as a general object the preparation of such starch grams of water to boiling, adding 100 grams of solutions in a convenient, efllcient and econom- Starch previously admixed with about 200 cc. of 5 ical manner. water thereto, and vigorously stirring the mix- 00 An object of the invention is to provide a ture until the starch is gelatinized, and theremethod of preparing starch pastes from readafter stirring the starch paste with a high speed ily available commercial forms ofstarch withmixer for about ten minutes. A suitable mixer out special pretreatment thereof, or subsequent s one such as is ordinarily used at soda founenzymatic treatment of the solution. tains and has a speed of about 11,000 R. P. M. 05

Another object of the invention is to provide The marked change in the physical propera method of preparing a starch paste having a ties of the starch paste thus produced is shown low viscosity, which has a homogeneous mm by the following table, showing time of outflow sistency, improved stability and penetrability, of the paste from a standard 100 cc. pipette and is especially suitable for sizing and llnishhaving an outflow time of 53 seconds for water; ing textiles, the three columns at the right showing check The invention accordingly comprises the sevsults. eral steps and the relation and orderof one or more of such steps with respect to each of the ominm Outflow time in seconds from others thereof, which will be exemplified in the Pipette at a method hereinafter disclosed, and the scope of unhomogeneous, of high viscosity, and has shown a marked tendency to gelatinize.

In accordance with the principles of the pres- Although the tlme in n cessa y W111 ent' invention, it is found that a starch paste depend upon the type of stirrer or null used, dehaving t h t t of as high as 1 can sirable results are found to be obtained when the be prepared, hi h will have uniform mixing is carried out in a manner and to a degree sistency, a relatively low viscosity, and w such that the outflow timeof a 5 starch paste main in a liquid form for period of several from astandard 100 c.c. pipette LS approximatemonths without gelatini'zation or precipitation. s y 200 ds 01' less at 2 1 0., or expressed in 0 These improved qualities have been obtained by other words, the outflow time of a 5% paste is a method requiring no special pret t t of approximately the same as the outflow time of a the starch used, and including no subsequent glycerol solution of 1.213 to 1.21 5-spec1fic gravity special treatment of the starch paste, but rather at the Same p rature from-a 100 ccp p v by a mechanical operation resulting in the uniand any improvement of the vlscoslty of t form dispersion of the starch and the rupture Sta-r011 98898 which attains this end 1 to be 0 or disintegration of at least a portion of the sidel'ed be Within the 56096 of the Present ncell walls of the starch granules in the paste. Ventlon- In its Preferred m n he in- This mechanicaloperation may be can-led out vention contemplates a further 511111181 treat- 45 in a number of ways without departing from mentof m after it has dthe scope of the invention; as for example, by- That Starch P t P p In a c rdtreating the starch paste with a high speed ance with the principles of the present invention mixer, for example a mixer having a speed pf differs from usual starch pastes which have not at least 1200 R. P, M., or passing 11; through been so treated is also indicated by the fact that 50 colloid mill or other type of mill giving similar if 3 Portion were 3 matedwith an mechanical efiects, as, for example, passing it l N between rapidly rotating and closely spaced m discs, such as a viniu in which the discs have a a clearance of 0.003 mm. iodine solution, the original starch paste stirred 55 As an example of a manner in which the presfor, only one minute showed a precipitate, whereno as those pastes stirred for six or more minutes showed no precipitate. This was also confirmed by microscopic examination, which latter indicated that a considerable amount of the cell walls of the starch granules were ruptured by the stirring treatment.

A starch paste prepared in accordance with the principles of the present invention, if poured on a lacquered metal sheet and dried over night, forms a transparent, uniform andfiexible film which indicates that in addition to the stability and. low viscosity features of the starch above mentioned, it should be very useful in sizing of textiles, and in dye-printing textile materials, and in the paste, paper making and food industries. Furthermore, it is desired to point out that the starch paste prepared in the above described manner through the action of a high speed mixer may be converted into a dry product, well adapted for a variety of purposes by forcing a low viscosity starch paste through a spray nozzle in the usual manner, and thereby contacting in spray form with a drying medium. In this manner the starch product may be effectively dried as in the manner above described, namely by pouring onto a lacquered metal surface.

Since certain changes may be made in carrying out the above method without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described our invention, what we claim as new and desire to secure by Letters Patent, is:

1. A method of preparing. a starch paste having high stability and low viscosity, which comprises cooking starch in water to gelatinize the same, and thereafter subjecting the hot starch paste to the action of a high speed mixer until its viscosity has been lowered to an extent such that'the outflow time of a 5% cold solution thereof from a standard 100 cc. pipette is approximately 200 seconds or lower.

2. A method of preparing a starch paste having high stability and low viscosity, which comprises cooking starch in water to gelatinize the same, and thereafter subjecting the hot starch paste to the action of a colloid mill until its viscosity has been lowered to an extent such that the outflow time of a 5% cold solution thereof from a standard 100 cc. pipette is approximately 200 seconds or lower.

3. A method of preparing a starch paste having high stability and low viscosity, which comprises cooking starch in water to gelatinize the same, and thereafter subjecting the hot starch paste to the action of a high speed mixer for a few minutes, allowing the paste to cool and thereafter subjecting it to a further treatment with a, high speed mixer until its viscosity has been lowered to an extent such that the outflow time of a 5% cold solution thereof from a standard 100 cc. pipette is 200 seconds or lower.

4. A new composition of matter, a gelatinized and vigorously agitated starch paste having a viscosity such that a cold solution thereof containing 5% starch has an outflow time of approximately 200 seconds or less from a standard 100 cc. pipette at a temperature of about 21? C.

5. A method of preparing a starch paste having a high stability and low viscosity which comprises gelatinizing starch and thereafter subjecting the gelatinized starch to the action of a high speed mixer.

6. A method of preparing a starch paste hav- 100 ing high stability and low viscosity which comprises gelatinizing starch and then subjecting the gelatinized starch to vigorous agitation until its viscc .lty has been lowered to an extent such that the outflow time of a 5% paste from a standard 100 cc. pipette is approximately 200 seconds or lower.

'1. A method of preparing starch paste having high stability and low viscosity which comprises cooking starch in water until the starch is gelatw inized and thereafter subjecting the gelatinized starch to vigorous agitation until its viscosity has been lowered to an extent such that the outflow time of a 5% paste from a standard 100 cc. pipette is approximately 200 seconds or lower.

8. A method of preparing a starch paste having high stability and low viscosity which comprises gelatinizing starch and subjecting the gelatinized starch to the action of a high speed mixer having a speed of about 11,000 R. P. M.

9. A method of preparing a starch paste having high stability and low viscosity which comprises heating about 100 parts of starch with about 2100 parts of water to boiling, stirring until the starch has been gelatinized and thereafter subjecting the starch paste to the action of a high speed mixer having a speed of about 11,000 R. P. M. for a period of about 10 minutes.

STEPHEN JOZSA. HERBERT C. GORE. 

